DERIVATIVES OF NAPHTAAQUINOLINES AND NAPHTHA[§
CharJes Stanley Gibson, Malvoi Venkalakrishna Bdariharan, Kottiazadh
Narayana Menon and John Lionel Simonsen.
By Charles Stanley Gi6son, Kalvoi Ve~chatdrishnaHarihavaz,
Kottiwath Nwayana Me~ton,a d John Lionel Simonse?~.
I n continuation oi the work (Gibson and Simonsen, J., 191j, 107,
148) which began with the stereochemical investigation of dl-tetra~ydro-P-naphthaquinaldine
(dl-3-methyl-I: 2: 3: 4-tetrahydro-$-naphthapinoline] i t has been necessary to study some derivatives of the
naphthaquinolines in greater detail than was at first anticipated.
Whilst the condensation of 8-naphthylamine and paraidehyde (Doeboer
and von MilIer, Ber., 1884, 17, 1 7 1 1 ) offers no difficuities, we have
not been able to isolate the a-naphthaquinaldine-2-methyl-a-naphthaquinoline-by
condensing a-naphthylamine with paraldehyde as
described by the above authors; in numerous experiments, apart
from unchanged material, we obtained only amorphous, brown solids.
It would appear, therefore, that these authors worked under conditions
which we have been unable to reproduce.
r
In order to obtain dl-tetrahydro-a-naphthaquinaldine [dl-n-methyl: 3 : 4,tetrahydro-a-naphthaquinoline]we studied the method
first adopted by Knorr (Ber., 1884, 17, 543) and subsequently investigated in greater detail by Conrad and Limpach (Bey., 1888, 21, 531).
T h e latter authors state that when a-naphthylamine and e:hjl
acetoacetate are heated together for a long period on the water-bath
ethyl B-I-naphthylaminocrotonate(I), is produced. Under these conditions we were able to isolate only acetoaceto-a-naphthalide (V), even
when a considerable excess of ethyl acetoacetate was employed. In
the presence of a small quantity of diethylamine, however, a-naphthylamine and ethyl acetoacetate readily condensed to give the desired
compound (I). This compound was not obtained crystalline, bur
when the oil was heated to 240° it was converted into 4-hydroxy2-methyl-a-naphthaquinoline(11). By the action of phosphorus
pentachloride the corresponding 4chLo~o-z-melhyC-a-napAth~~~i?toI'i~tc
was easily obtained and this was reduced with sodium and ethyl alcohol
I
:
2
'Reprinted from ths Journal o. the Cheaical Soci~fy, 1826, 2247.
Tba name
naphthaquinoline is in established nse and hence also the mice naphth.?iroqninoiine hns
been adopted in the present cammunicstion. It should be pointed orit, hmeYrr, that :ha
names benzoquinoliue arid benzoisoqainoline would be prefeiable, ,as being in accorrlmce
with the syrtem on rnhlch ths majority of composite names of ring systems is dwised ;
but no alteration is suggested, as the introduction of fresh synonyms is undesirable.
to the desired compound, dl-n-ntetkyL-I: 2 : 3 : ~-tcti,nkyc!?-@-~-~z~r$hikapttiwolisre (111). 'This is the coinpound that shoulcl he obtained by the
reduction of the base which Doebner and von Miller describe as having
been prepared by the condensation of a-naphthylamine and paraldebyde. The compound is an oil which was readily characterised by
the Preparation ol a number of derivatives.
Under the conditions described by ICnorr (loc. cit.) n-naphthylmine and ethyl acetoacetate alone yield only a small quantity of
?-1-naphihy~nmfizoc~ot(1r'~3-1-7z~zphtk~!~ai~zidz
(IV), the chief product of thc
-eaction being a colourless, non-basic, high-melting sulsstance A
:p, 185). Under the conditions described later, thc amount of (IV)
~btained is much more satisfactory. This compound exists in two
nterconvertible forms (see the experimental section), but it has not
>een determined whether this is a simple case of dimorphism or
whether the two forms represent the possible cis- and trmns-modifica:ions.
The crotonyl derivative was readily converted into acetoacetoc-naphthalide (V) by hydrolysis with dilute hydrochloric acid, but the
onversion of this product into ~-hydroxy-4-metl~yl-a-naphthaquinoline
VI) by means of concentrated hydrochloric acid presented great
lifficulties on account of hydrolysis and the Production ol a-naphthyl[mine. Sufficient of the hydroxy-base was obtained, however, for the
)reparation of the corresponding chlbro-compound and the reduction
I£ the latter to dl-/l-incthykr : 2 : 3 : 4-tetmhydro-a-~zn$Ltriapui~zoline
VII). This base does not give a crystalline de~zzoylderivative, but it
s readily characterised by its crystalline picrate.
During the course of this work very marked differences i n the
behaviour of a- and 2-naphthylamines towards paraldehyde and ethyl
acetoacetate were repeatedly noticed, and similar dificulties in obtaining derivatives of a-naphthaquinoline from a-naphthyiarnine were
eilcountered by John and his collaborators (J. $7. Chem., 1925, 118.
65 et seg.). Experiments to throw light on this problem have shown
that, unlike a-naphthylnmine itself, 4-nitro-a-naphthylamine and
4-bromo-a-naphthylamine both condense readily with paraldehyde,
(V311) and 6-di*ov~o-2yielding 6-niLvo-2-i?zethyka-rznPhthaf?~z?zodi7ze
~zeth~l'-u-rta~hLbaq~~i~zoLii~e
(IX) respectively. Mr. Unni Nair arid one
of us (J. L. S.) have also recently found that 4-a~ninoacena~hthene
condenses readily with paraldehyde, and thus we have definite
evidence that substitution in the 4-position in 0.-naphthylamine seelns
to be a determining factor in making a-naphthylamine behave more
nearly like 8-naphthylamine.
By condensing ,+naphthylamine and ethyl acetoacetate under the
conditions described later (p. 187; compare Icnorr, ioi-. cif., and
Conrad and Limpach, [DL. cit.), g-2-~za~hth~~Zam~au~~oto~zo-z-1zaphth~ia
mzdz (Xj was readily obtained. From this con~pound,by hydrolysis
(XI) was prewith dilute hydrochloric acid, aretoaceto-,g-~zap/zthaiiilc
pared, and this, when heated with concentrated hydrochloric acid, was
(XII). By reacconverted into 3-hyd~oxy-1-r,zethyI-~-1ll~phdh~ui1zoZi9te
tions which have already been indicated, the correspouding j-chl'ovor-~~~ethy~-,~-?za$hthaqzi'~~o~~?te
and dI-~-~~zlz~z%yZ-r
: 2 : 3 : 4-iefmah~~dm,g-,~.zph~hag&oIim (XIIIJwere obtained. This externally compensated
base, like the analogous one prepared from a-naphthylan~ine,is a
viscous oil which crystaliises in liquid air. Its denzoyl derivative could
not be obtained crystalline, but t!lc crystalline p i d m t e serves for its
easy characterisation.
Under suitable conditions, the reaction between E-naphthylamine
a x ! ethyl acetoacetate g:ies differectly from that described above and
a colourless non-basic, high-melting substance, A (p. I S S ) , is fonned.
This is isoiceric with substance A (p. rSj), d h which ~t has been
carefclly compared. T h e su.bstances A and B are u;~doabtediy ihe
ureas, C O (NH.C,,M,),, of ct- and ,c-napbthyla:r:i:~e respectively and
tIleir fummtiori is esplicable bj; thc niechmisn~ suggested by Hilrst
3
and Thorpe (J., 1915, 8 07, 93; ; compare Ewiils and Ring, J ., 1915,
103, 104 ; Young and Clark, J., r897, 71. 1200).
Q
L he possible occurrence in nature of iiapllthaisoquinoline derivatives made it desirable to atreinpt the preparation ol compounds
having this ring structure, no representatives of which seem to have
been described. O u r work is based on that of i<auimann and
Radosevic (Rev., 1916, 49, 6 f j ) , who treated the oximes of substituted yketobutylbenzenes with phosphorus pentoxide and obtained
methyldihydroiroquindinr derivatives.
T h e considerable quantities ol a- and B-naphthaldehydes required
were convenientiy prepared by Sonn and Miiiler's method (Rev., 1919,
52, 1927). a- And 8-naphthaldehydes condensed readily with acetone
to give I - and ~ - ~ - k e L 0 6 z t t e ~ t j t ~ ~ z n f h t A n I c ~Cl,1-f;CW:CH~COMe,
zes,
respectively, from which the corresponding 7-ketnbz~tyl~za~hi'haZe~tes,
C,,H,~CK,~CH,.COMe,were obtained by catalytic reduction. These
were converted into the corresponding un-imzes, and, although the
pieparation from these of the dihydrobases was attended by the
forniation oi much resinous by-product, sufficient ~ n z e t h y G r: ~ & u i % ~ 8-?t~fhfh~iso~~tifz~~i72~
( X I V ) (from a-naphthaldehyde) and I-methyl3 :4-dihyd~u-n-na$/1thaisoqui~~oii~ze
(XV) (from B-naphthaldehyde) were
obtained in the crystalline condition for identification. T h e following
scheme represents the formation of these compounds.
T h e stereocheniical investigatioll oi the externally compensated
bases now described is in progress.
EXPERIMENTAL.
Colldematiaa of a-NxphthyZamim a u d E t h y l Aceioncefate.--A
mixture of ethyl acetoacetate (13 g.) and a-naphthylamine (14.3 g.)
containing 2 drops of 3396 diethylamine solution became cloudy in a
few hours and the calculated quantity of water had separated in 3 days.
T h e thick, red oil was extracted with ether, the solution dried, and the
ether distilled. T h e residual oil, when heated at 240°, was converted
into a crystalline solid, which was ground with alcohol and crystallised
from amyl alcohol or nitrobenzene. A s stated by Conrad and
(IT) did not melt
Limpach, the ehydroxy-2-methyl-a-naphthaquinoline
below 300° (Found : N, 7.1. CaIc. : N, 6.7%).
4CkZoro-2-methyZ-a-~znphthaguinoGine.-A mixture of 4-hydroxy2-methyl-a-naphthaquinoline(10 g.), tetrachloroethane (20 c.c.) and
phosphorus pentachloride (10 g.) was heated at 130--r40° for 2 hours
and finally at r60--17oO for I hour; evolution of hydrogen chloride
had then ceased. The clear, deep brown solution, which deposited
crystals on cooling, was poured on to i c e ; the greater part of the
chloro-derivative separated in the form of the sparingly soluble
hydrochloride. A solution of this in hot water was filteredfrom a little
tar and basified, the chloro-derivative separating as a colourless,
crystalline solid. A further quantity was obtained from the
tetrachloroethane solution by removal of the solvent with steam
and basification of the filtered acid solution. 4-ChZoro-~-methyZ-anafihthapwinoZi~ze
crystallised From alcohol, in which it was somewhat
sparingly soluble, in long needles, m. p. 92--93O (Found: N, 6.6.
C,H,,NCl requires N, 6.2%). T h e picrate, prepared from equivalent
quantities of the base and picric acid in alcoholic solution, separated
in yellow prisms, m. p. 196-rg?O, which could not be recrystallised
owing to their sparing solubility.
(III).--To a
dl-2-Methyf-I:2 : 3 :4-tetrahj1rlro-a-napht/IagzcinoZi~e
solution of 4-chloro-2-methyl-a-naphthaquinoline(20 g.) in boiling
alcohol (900 c.c.), sodium (60 g.) was added as rapidly as possible.
When all the sodium had dissolved, the alcohol was removed i n steam,
the residual oil extracted with ether, and the ether dried and
evaporated. On distillation under diminished pressure, the base was
obtained as a pale yellow, somewhat mobile, uncrystallisable oil,
b. p. 202-203O'20
mm. In solution i t showed a marked blue
fiuorescence (Found : C, 8 j-o; H, 6.0. C,,H,,N requires C, 85-3 ; H,
7.6%). T h e bemqd derivative crystallised from methyl alcohol, in
which it was readily soluble, in clusters of colourless needles,
in.p. 102-lo3O (Found : N, 4.7. CzlHleON requires N, 4.6%). T h e
&drochZoride crystallised from hot dilute hydrochloric acid, in which
it was somewhat sparingly soluble, in glistening prisms, decomp.
2 j z - 2 ~ 3 (Found
~
: Cl, 15.2. C,,H,,N,HCI requires Ci, ija2%). The
szdphate crystallised from dilute sulphuric acid in iridescent ~ r i s m s ,
(Found: S , 10.6. C14H,,N~H2S0, requires
decomp. 211-212~
S , 10.9%). The chloropZnh?zar'ewas a very sparingly soluble, brown
powder, decomp. 207-208~.
T h e $icrate crystallised from dilute
alcohol in fine, yellow needles, m. p. 88--8g0.
These evi?entiy
coatained solvent of crystallisation, for, after being dried in a vacuum
over calcium chloride ~ r i o to
r analysis, they melted a t 153-154~ and
decomposed at a slightly higher temperature (Found : N, 13.4.
C,,H,,G,N, requires N, r 3.1%).
p-r-Napkthyl~nzi?zoc~oL'o~zo-~-~za~12tkyInrnide
(IV).--A mixture of
a-naphthylamine ( 2 mols.) and ethyl acetoacetate ( I mol.) was
heated on the water-bath for 24 hours and then at 150--17o~ for
4 hours. T h e semi-solid red condensation product was extracted
with boiling 58 per cent. alcohol ; a considerable quantity of the
crystaliine solid A remained undissolved. T h e filtrate, when kept in
the ice chest, slowly deposited 6-I-na$hthliyZami?zo~~oto~o-I-~znpRthyGnsnide, and a further quantity was obtained by removing the alcohol and
grinding the residue with benzene or light petroleum. T h e substance
usually sePrated from the alcoholic solution as a fine, crystalline
powder, m. p. 135--145', but occasionally it was deposited in wellformed needles, m. p. 145-147'.
It was apparently dimorphous and
the crvstalline form and rn. o. varied according t o the solvent use3 for
crystailisation. LVhcn crysthlised from a!xol& alcohol, the ci~mpoucd
separated i n well-formed, prismatic needle.;, m. p. 167-!6S0, am! this
mIp. was unaltered by ;ecrystailisation from this' solvent. From
benzene, the compound was deposited in fine, silky needles which
softened at 135' and melted at 144-145'.
Crystallisation of the
substance of hieher rn. p. from benzene yielded the form, m. p. 14414j0, which could be reconverted into the form of higher m. p. by
crystal!isationfrom alcohol. T h e lower-melting form was also convert ~ into
d the higher-melting form by heating it above its melting point,
since, after solidification in the m. p. tube, the m. p. was 167-168".
Both forms had the same composition (Found : {I) C, 81.8 ; H, 5.6.
(2) C, 81'3; H , 6.0.
C2,H2,0N2requires C, 81%; H, 5.7 per cent.).
-
-
Acetometo-a-napktbaGide(V) was obtained in a quantitative yield
when the preceding compound was digested on the water-bath with
4 per cent. hydrochloric acid for t hour. I t crystallised from benzene
in needles, m. p. 1 0 7 ~(Found : N, 6.2. C,,H,,O,N requires N, 6.2
per cent.).
T h e finely divided naphthalide, after remaining in contact with
concentrated hydrochloric acid for some weeks, was converted into 2 hydroxy-4-methyl-a-naphthaquinoline(VI), which crystallised from
alcohol in needIes having the m. p. recorded by Knorr.
z - Chbro-4-m~thyl-cl-napht/zag2~i1~oIi1ze
was obtained when the
hydroxyquinoline was heated at 130-140' with the required amount
of phosphorus pentachloride for z hours. The product, after treatment
with dilute alkali, was dissolved in cold concentrated hydrochloric
acid, filtered from a little resin, and precipitated by addition of water.
I t crystallised from alcohol in prisms, m. p. 134- 1 3 5 ~(Found : CI,
C,,H,,NCl requires C1, 15'6 per cent.).
I 5.3.
dl-4Methyl-I : 2 : 3 : +tetrahydro-a-naphfkag?~inoZine(VII)! prepared by reducing the preceding chloro-compound under the cond~tions
employed in the reduction of 4-chloro-2-methyl-a-naphthaquinoline
(see p. 183), was obtained as a viscous, pale yellow, uncrystallisable
oil, b, p. 186-188~/ ro mm. (Found : C, 85.0 ; H, 7-8. C14H,N
requires C, 85'3 ; H, 7'6 per cent.).
I t showed a bluish-green fluorescence in benzene or alcohol and
the solution darkened rapidly on exposure to the air. The sulphate
and hydrochloride were somewhat readily soluble in water, the
hydrobromide more sparingly soluble. The pzcrate crystallised from
much alcohol in pale yellow prisms, decomp. 2 0 j-206~ (Found : N,
13'6. C,H,,O,N, requires N, '3.1 per cent.).
The substance A proluced in the condensation of a-naphthylamine and ethyl acetoacetate (seep. 184) became the main product if
the preliminary heating on the water-bath was omitted. It was very
sparingly soluble in all the ordinary solvents and bad no basic
properties. I t crystallised from much acetic acid or from nitrobenzene
in fine needles, decomp. 280°. When distilled with zinc dust, or heated
with hydrochloric acid or alcoholic potassium hydroxide in a sealed
tube at rjou, it gave mnaphthylamine only, and oxidation with
potassium permanganate in acid solution produced phthalic acid
(Found : C, 81.05, 8 0 9 ; H , 5 . 1 , 5.15 ; N, 9.0, 8.9. Calc. for
C,,H,ON, : C, 80.8 ; H, 5.2 ; N, y o per cent.). It was proved to be
the urea of a-naphthylamine by comparison with an authentic specimen.
Co~ufematio?~
o f 4-~7itro-a-aaphthyi~~>zi7z~
mzd Pa~aL&Ayde.--A
mixtwe of 4-nitro-a-naphthylamine (20 g.), concentrated hydrochloric
acid (40 g.), and paraldehyde (30 g.) was heated at 110-11 jnfor 4
hours with constant agitation. The cooled reaction mixture was
poured into water, the solid collected and repeatedly trLturated with
concentrated hydrochloric acid. The filtered solution was diluted
with water until no further precipitate formed, and after remaining
over-night the yellow solid, which was not investigated, was removed
and the acid solution basified. The dark brown solid thus precipitated
was dried (5 g.) and repeatedly extracted with boiling light petroieum
(b. p. 60-Po5), which left undissolved a considerable quantity of
carbonaceous matter. The petroleum so!ution slowly deposited a
greenish-yellow, crystalline soiid which, after recrystai!isation from
alcohol with the aid of aninla1 charcoal, wzs obtained in soft, yellow
needles, m. p. 141-142' (Found : N, 11.8. C14Hlo0,N2requires N,
I I .8 per cent.).
6-Ni~v~-z-meihyka-~1nphtAn~z~i7to~i11e
( V I I I ) is very soluble in a11
the ordinary organic solvents except alcohol and light pe:ro!eum.
T h e sulphate and hydrochloride are readily soluble in water; the
nitrate, which crystallises in needles, is less soluble. T h e chloyoplahmztc is very sparingly soluble in water, crystallising in glistening,
golden prisms, decomp. 229--zjo0 [Found : Pt, zz.5. (C14HIo02N2)29
H,PtCl, requires Pt, 2 2 ' 0 per cent.].
Condensatiom of 4-B~omo-a-nupRt/lyZa~~ine
and Prr~aZdeh~rde.--A
mixture oE 4-bromo-u-naphthylamine hydrochloride (10 g.), paraldehyde
(15 g.) and hydrochloric acid (zo g.) was heated at I 10" for 4 hours.
T h e cooled reaction mixture was mixed with alkali, and the deep brown
solid which separated was collected. This was dissolved in hydrochloric acid, the non-basic impurities were separated by filtration, the
solution was boiled with animal charcoal, and the mixture of bases
reprecipitated with alkali. T h e crude bases were collected, dissolved
in dilute sulphuric acid, treated with an excess of sodium nitrite
solution to remove any primary and secondary bases, and the filtered
solution basified. T h e crystalline base ( 2 g.) was purified by solution
in light petroleum and finally recrystallised from methyl alcohol, from
which it separated in colourless, felted needles, m. p. 99--100" (Found :
N, 5.1 ; Br, 29.4. C,,H,,NBr requires N, j.1 ; Br, 29.4 per cent.).
6-B~orno-2-methyka-?zapht6aquinodi~te
(IX) is readily soluble in
benzene, ethyl acetate, or light petroleum, and more sparingly soluble
inethyl or methyl alcohol. I t is insoluble in water. T h e hydrochloride separated from concentrated hydrochloric acid in needles
which were readily soluble in water. T h e hydrobromide was somewhat
moresparingly soluble and crystallised in prismatic needles. The
chZompZati~zale was a microcrystalline, brown powder, very sparingly
soluble in water or dilute hydrochloric acid ; it decomposed at 238"
(Found : Pt, 20.2. (C14H10NBr)2,HLPtClsrequires
Pt, 20.4 per cent.).
T h e picrate separated from alcohol, in which it was very sparingly
soluble, in glistening, yellow prisms, m. p. 185-I%",
and slowly
decomposed above this temperature (Found : N, 11.6. C,,H,O,N,Br
requires N, 11.2 per cent.).
Co?uZensaiwn o f P-Naphthylamir~e arzd Ethyl Acctoacetatc.--3Hydroxy-I-methyl-P-naphthaquinoline
( X I I ) was most conveniently
prepared by the following modification of Knorr's method (bc. 6 2 . ) .
A mixture of B-naphthylamine (2 mols.) and ethyl.acetoacetate (I mol.)
was heated on the water-bath for 1 2 hours andat 150--180" fcu 3 hours.
T h e crystalline magma thus produced was cooled, crushed, and after
removal of a little adherent oil, was well washed with hot alcohol.
(X) was disT h e crude B-2-naphthylaminocrotono-2-naphthylamide
solved in much boiling xylene and filtered from a small quantity of
sparingly soiuble residue, B (see below) (yield 71 per cent.). The
properties of the recrystallised substance agreed in ail respects with
Knorr's descripticn. Acetoaceto-8-naphthalide (XI) was prepared
from it by Knorr's method ; the solution, however, was not boiled, the
hydrolysis taking place readily on the water-bath. The naphthalide
separated, on cooling, as a curious, gelatinous solid which could not be
filtered and was therefore isolated by extraction with ethyl acetate, in
which it was very readily soluble (yield 94 per cent.).
3-Hydroxy-I-methyl-3-naphthaquinoline
was obtained when the
naphthalide was heated on the water-bath with concentrated hydrochloric acid. If the solution was boiled as recommended by Knorr, a
considerable quantity of B-naphthylamine was formed simultaneously.
When distilled with zinc dust, the hydroxy-compound gave a poor
yield of I-methyl-P-nap'nthaquinoline, m.p. 91-92", the picrateof which,
after crysta!lisation from much alcohol, melted at 230-231' with
. ~
requires N, 13.3
previons softening (Found: N, ~ 2 CaH,0,Ns
per cent.).
3-C/lloro-~-r~~eiA~~l-P-~zap~tkaqui~toZi~z.-A
mixture of j-hydroxyI-methyl-8-naphthaquinoline (5 g.), tetrachloroethane (10 c.c.), and
phosphorus pentachloride (5.5 g.) was heated a t 170-180" for 3 to q
hours. T h e solvent and the phosphorus oxychloride were then
removed under diminished pressure, and the residual solid, after
trituration with dilute alkali, was crystallised from alcohol ; the chlo~ocompound was thus obtained in colourless needles, m.p. 153-154"
(yield 95 per cent.) (Found : CI, 15'6. C,,H,,NCI requlres C1, 15.6
per cent.).
(XI I I) was
dl- I -M&yl-I : 2 : 3 : 4-tetv~~h~tdvo-~-nap/zt~a~~(inoli~~e
obtained when 3-chloro-I-methyl-B-naphthaquinolinewas reduced
under conditions similar to those employed for the preparation of dl-2(p. 183). The greater
methyl-I : 2 : 3 : 4-tetrahydro-a-naphthaquinoline
part of the base distilled at 188-195",' 10 mm., but was contaminated
with a considerable quantity of resinous impurity which was only
removed with diiCF,culty by fractional distillation. The base was
therefore converted into the picrate, which crystallised from alcohol in
pale yellow needles ; these decomposed at 162", and at 167-168" when
rapidly heated (Found : C, 56.2 ; H, 4.4 ; N, 13.1. C,&,,O,K';,
requires C, 56.3 ; H, 4.2 ; N, 13.1 per cent.). During the purification
of the picrate a very small amount of a very sparingly soluble picmie
was separated which crystallised from a large volume of alcohol in
This picrate had the same
glistenicg, yellow leaflets, m.p. 201-202'.
composition as the picrate, m. p. 162" (Found ; C, 56.1 ; H, 4.2
per cent.), but it was not obtained in suiiicient quantity for investigation.
dl-~-Met/lyG~
: 2 : 3 : 4-tetrahydro-p-naphthnguinoIi~t8
revenerated
from the picrate was a thick, yellow oil, b. p. r 8 7 - - ~ 9 0 0 7 ~ omm.,
which darkened rapidly on exposure to air (Found : C, 84.8 ; H, 7.6.
C,,H,,N requires C, 8 5.3 ; H, 7.6 per cent.). It showed a blue
fluorescence in benzene solution. It did not solidify in a freezing
mixture. but at the temperature of liquid air it set to a crystalline
mass of long needles which melted at room temperature. The hydrochloride was readily soluble in water ; the sulphate, which crystallised
in needles, was not so soluble.
The sparingly soluble substance B, obtained during the condensation of p-naphthylamine and ethyl acetoacetate was formed in much
larger quantity if the preliminary heating on the water-bath was
omitted. This substaace (compare substance A, p. 185) was insoluble in all the ordinary organic solvents, but crystallised from nitrobenzene in large, colourless needles sintering a t 288" and decomposing
at 2g3-29+' (Found : C, 80.8, 80.8 ; H, 5-1, 5.1 ; N, 8.9, 8.95 per cent.
Calc. for C,H,,ON, : C , 80.8 ; H, 5.2 ; N, 9.0 per cent.). I t was
shown to be the urea of 8-naphthylamine by comparison with an
authentic specimen.
I-MetlTyZ-3 : 4-dihyrlro-a-~za$hi'haisoguinoIin~
(XV).-For
the preparation of 8-naphthaldehyde, a mixture of 8-naphthadid8 ' (8 g.),
tetrachloroethane (25 c.c.), and phosphorus pentachloride (7 g.) was
heated at 140-r50° until evolution of hydrogen chloride ceased ( I
hour). The phosphorus oxychloride and a part of the solvent were
removed under diminished pressure ; on cooling, the iminochloride
separated as a yellow, crystalline solid. This was redissolved in
tetrachloroethane, and the solution gradually added to an ethereal
solution of stannoas chloride saturated with hydrogen chloride (ether,
250 C.C. ; stannous chloride, 30 g.). A somewhat vigorous reaction
took place and the stannichloride of the Schiff's base separated as a
yellow, gelatinous solid. After some hours, the ether was decanted
from the salt, dilute hydrochloric acid (50 c.c.) added, and the aldehyde
distilled in steam (yield 80--go per cent.).
2-r-Keto6utenylnaphthaZene.-A mixture of the aldehyde ( I part),
acetone (6 parts), water (30 parts), and 2 0 per cent. sodium hydroxide
' Thksubstance ~IYStdlkedfrom alcohol, in which
cd0urlff.i prisllls, m. p.
it was suinewhat sparingly S
171* (Pound : N, 5.8. C17H130N requl- N, 5.7 per cent.).
U ~ U U in
~ ~ ,
soiution (0.2 part) was agitated, and occasionally warmed on the
water-bath, for a or 3 days. The aldehyde gradually liquefied and
remained as a semi-solid oil until the condensation was nearly
complete ; the butenyl derivative then separated as a crystalline solid.
When the reaction was complete, the solid was collected and dissolved
in benzene, a small quantity of di-p7zap/ithyZniayZ keQae (see below)
remaining undissolved.
T h e benzene solution was dried and
evaporated.
2-yKetol;u~e7~ylnaphthaie~ze
separated from methyl alcohol in
nodules of yellow needles, m. p. 1oa0, after sintering at gj--96% I t
was readily soluble in the ordinary organic solvents, but very sparingly
soluble in water (Found : C, 8j.j; H, 6.3. C,aH,zO requires C, 85.7;
H , 6.2 per cent.).
Di-p-~zaphthyZwi?zyIketone, CO(CH:CH.C,,H,),, which was only
formed in traces when the condensation of P-naphthaldehyde and
acetone was carried out under the above-mentioned conditions, formed
the main product of the reaction when a solution of the aldehyde in
acetone was treated with a drop of a sodium methoxide solution. It
was very sparingly soluble in most of the ordinary organic solvents,
but crystallised from hot toluene in fine, sulphur-yellow needles, m. p.
2 4 1 ~(Found : C, 89.5; H , 5.6. CZJHIIO requires C, 89.8 ; H,
5.4 per cent.).
2-~-Oxinzimo6ut~1tyZ~za~htha~~w,
prepared by treating the corresponding ketone with hydroxylamine hydrochloride and sodium
acetate in absolute-alcoholic solution, crystallised from methyl alcohol
in glistening plates, m. p. I 58--160". Indications of the presence of
an isomeride in the mother-liquor were obtained, but this was not
isolated in a pure state (Found : C, 79'7 ; H , 66. C,,H,ON requires
C, 79-6 ; H, 6.2 per cent.).
2-y-KetobartyZnaphthaZ~9~8
was readily obtained in a quantitative
yield when the unsaturated ketone, suspended in acetic acid, was
reduced, in the presence of colloidal platinum, by hydrogen under a
pressure of 2 atmospheres. I t was a somewhat viscous, colourless oil,
b. p. 180-132~ 8 mm. In alcoholic solution it gave no colour with
ferric chloride (Found : C, 84'6 ; H, 7.3. C14H110 requires C, 84.8 ;
H, 7 . 1 per cent.). The oscztise crystall~sedfrom methyl alcohol in long,
glistening needles, m. p. 1 2 9 ~(Found: N, 6.8. ClcHlsON requires
N, 6.6 per cent.). The setnicrc~bnzoneseparated from methyl alcohol in
small prisms, m. p. 161-16.O
(Found : N, 16.6. C,,H,,OrU', requires
19, 16.j per cent.).
I-:WethyZ Q :~~ti/ij~d~o-~-i~nphtkaisoyz~t~~oZie
(XV).-A
n~ixtcre
of the oxime (6 g.), toluene (60 c.c.), and phosphorus pentoxide (10 g.)
was boi;ed with constant agitation for thirty minutes; phosphorus
pentoxide (10 g.) via5 again added and the heating continued for I
hour. T h e toluene was decanted from the cooled reaction mixture,
and the phosphorus penioxicle dissolved in ice water; a considerable
cjuantity of red tar then separated. T h e aqueous extract, which had a
blue fluorescence, was separated, extracted with ether to remove any
neutral products, and basified with potassium liydroxide solution.
T h e thick, colourless oil that separated was extracted with ether, and
the ethereal solution dried and evaporated (yield 1 . 2 g.). T h e crude
oily base was dissol-ied in alcohol and treated with the calculated
quantity of an alcoholic solution of picric acid ; the picvnte, which
separated in sparingly solubIe, yellow prisms: was recrystallised from
(Found : C, 56.8 ; 1-1,4.4 ; N,
acetone ; it decomposed at 207-205'
requires C , 57'9 ; H , 3.8; N , 13'2 per cent.). The
13.3. C,,FI,O,N,
dnse regenerated from the picrate solidified when cooled in a freezing
mixture. I t had 171. 11. 36-37") and this m. p. was unchanged by
crystallisation fromdilnte mcthyl alcohol, from which the base separated
in glistening leaflets, containingapparently a molecule of methyl alcohol
C11H1SN,CH3.0H
of crystallisation ( F o u ~ d: L, 79.8 ; FI, 7.1.
requires C, 79.3 ; H, 7-3 per cent.).
4-iTf8thjrZ-I : ~-dihydro-i3-~npht/ioisog~~i~~obt:e
(XIV).-The
anaphthalcie'nyde was prepared from a-u~phthatziiide under cxactly
similar conditions to those used for the preparation of B-naphthaidehyde (yield 75 per cent.).
'
r -1-KetodutegzyZfzapLtAabe?ze was prepared in a similar ma.nner to
the 2-isomeride (p. 189). I t was obtained a s a pale yellow, unI O
(Found : C, 85'2 ; H*5;9.
crystallisable oil, b. p. ~ ~ O - Z O I ~ ~ mino
C,,H,,O reqc~iresC,55.7 ; 3 , 6.2 per cent.).
r-~-Oxiiniito6uie~zyZ~znpAt~~Ze~zc
crystallised from methyl alcohol in
small nodules, m. p. 136-137" (Found : N, 6.6. C,,H,,ON requires
N, 6.6 per cent.).
I-r-Xefodatyd~znphthaZee,readily obtained by the recluctio:, of the
~nsaturated ketone with hydrogen in the presence of colloidal
platinum, was a colourless, mobile oil, b. p. 192-195~117 mrn., having
n pleasant smell reminiscent of acetophenone (Found : C, 84.8 ; W,
7.1. C,,H,,O requires C , 84.5 ; H, 7.1 per cent.). T h e oxime crysin long, glistening
tallised from light petroleum (b. p. 60-80")
needles, rn. p. 96-g7IJ.
I t was readily soluble in most of the usual
organic solvents (Found : N, 7.0, C,,H,,ON requires N, 6.6 per
cent.).
' a-ivofihlhanilidecrystallised Iron; alcohol i n prisn:~, m. p. 162-163°
ClsliuOiN requires N, 5.7 per cent.).
(Pound :
r,5.8-
4-MethyG~: 2~dihydvo-/3-aa@hLhaisogz~inoline
was obtained from
the oxime by the method employed for the prepwation of the isomeride
(p. 18p). After removal of the ether, the base crystallised immediately rn colourless needles which darkened rapidly on exposure to air.
It crystallised from dilute acetone in glistening needles, m. p. 101102" (Found : N, 7.2. C,,H,,N requires N, 7.2 per cent.). I t was
very readily soluble in all the ordinary organic solvents, but insoluble
in water. In benzene solution it showed a marked blue fluorescence,
which was also shown in other solvents but in a less marked degree.
T h e hydrochioride was very readily soluble in water, and the solution
gave, on the addition of platinic chloride, a very sparingly soluble
chloroplatinate, which separated as a brown, microcrystalline powder.
T h e picmte crystallised from a large volume of alcohol or acetone, in
both of which solvents it is very sparingly soluble, in fine, sulphuryellow needles which darkened at 2 1 4 ~and decomposed at 22x0
(Found : C, 56.8 ; I-!, 4.4. CZOWl6O7N(
requires C, 56-9 ; H, 3.8 per
cent.).
W e wish to express our thanks to Messrs. Windle and Bhagvat
for carrying out several of the analyses, to Mr. S. Karayan Iyer for
his help with the catalytic reductions, and to the Government Grant
Committee of the Royal Society for a grant which !;as defrayed part
of the expense of this investigation.
Gzby's Hospital Medicat Sc.4002,
Londofz, S.E.
Department o f Ovgnzic Chemistry,
11~dia~z
htsiifwie o f Scienc~,
Bn7zgaZort~.
[Accepted,
I 7-1 I -26.1
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